Sounds like Favre has "arm fatigue." I think the Jets made a big mistake: http://sports.yahoo.com/nfl/news;_y...?slug=ap-jets-fatiguedfavre&prov=ap&type=lgns
I think its obvious that Favre has a strong arm. As for his arm being fatigued, I think its more of him not taking part in the off-season activities. I think he sat for a while and then when he said he wanted to come back to the public, he started working out again at a local high school. He'll be fine imo. Also, from the article:
Not that big of a deal IMO. I would be much more concerned with a QB that never has any arm strength even when he is fresh.